Annealing-oven



J. D. GREEN.

ANNEALING OVEN.

APPLICATION FILED JUNE 11. 1920.

Patented Nov. 30, 1920.

Egvvuentoa 1/5 7: hi Green TENT OFFICE.

JOHN D. GREEN, or YPSILANTI, MICHIGAN.

ANNEALING-OVEN.

' Specification of Letters Patent. 7

Patented Nov. 30, 1920.

Application filed June 11, 1920. Serial No. 388,089.

ToaZZ whomz't may concern:

Be it known that I, JOHN D. GREEN, a citi zen of the United States of America, residing at Ypsilanti, in the county of Washtenew and State of Michigan, have invented certain new and useful Improvements in Annealing-Ovens, of which the following is a'specification, reference being had therein to the accompanying drawings.

The invention relates to annealing ovens and has for its object ,first, the obtaining of effective heat insulation for the oven walls; and second, the construction of these walls 7 of units, which may be easily assembled to produce ovens of varying dimensions.

In the drawings:

7 Figure 1 is a perspective View of the oven;

Fig. 2 is a cross-section thereof; Fig. 3 is a longitudinal section.

For the annealing of metals, such as tool steel, malleable iron, castings etc., it is necessary to provide an oven which will withstand the high heat of the articles when first placed therein, which has sufficient strength to sustain the load and which is provided with heat insulation for retaining theheat for a long period. It is a known fact that a vacuum chamber furnishes effective heat insulation, but as such chambers are usually formed of glass, they are inapplicable to annealing ovens. With my invention I have provided vacuum chambers in the walls of the oven without diminishing the mechanical strength of the structure. I have also provided. a construction in which the walls are formed of separate units. As shown, A is one of the unit sections formed of an outer wall B and an inner wall C parallel to the front and rear walls D and E and mitered edges F and G. In the construction of this unit the several walls are properly formed by pressing or otherwise and are united to each other by welding so as to make an air tight structure. At the mitered edges there are provided projecting flanges Ifwhich have registering apertures therein for the reception of clampin bolts.

ithin the oven chamber is arranged a lining of refractory material, which as shown is formed of slabs K rabbetted to interlock with each other. One end of the oven chamber may be closed, either by a solid slab or preferably asshown by a hollow slab L, which also constitutes a vacuum chamber. At the front there is provided a door frame M to whichis hinged a door N for closing the opening. Each of theunits is provided with a nipple 0 containing a valve and the arrangement is such that the air may be exhausted from the compartment by a vacuum pump connected to said nipple, the valve closing to prevent the filling of the chamber when the pump is removed.

here the oven is designed to carry a considerable weight, there would be danger of the bending or distorting of the bottom thereof. To avoid this I have reinforced the bottom sections by the insertion of an I-beam P therein.

In assembling the structure a number of units may be employed, according to the dimensions required and after these have been bolted to each other, the refractory lining plates K are introduced. The end slab L is then secured to one end of the unit and the door frame M to the other and if desired, the refractory or heat insulating material may be placed between the frame M and the adjacent oven sections to avoid heat losses therethrough. When the structure is complete, the heat in the work when first introduced into the oven will be retained for a relatively long period, so that the cooling is very gradual and will give opportunity for a re-arrangement of the molecules so as to avoid stresses.

\Vhat I claim as my invention is:

1. An annealing oven comprising inner and outer metallic walls sealed to form a vacuum chamber therebetween, and a refraltlrtory lining for. protecting the inner wa 2. An annealing oven comprising inner and outer metallic walls forming a vacuum chamber therebetween, reinforcements for supporting the bottom of the inner wall,

chamber, and means for clamping the beveled ends of adjacent units to each other.

5. An'annealing oven comprising-a plu rality of units each consisting of an 'inner and an outer metallic Wall and connecting flanges Welded to form a sealed joint and a vacuum chamber between said Walls, the

end of said units-being beveled and provlded With flanges extending beyond the same, and means for clamping the flanges of adjacent units in the formation of an oven chamber. 7

'6. An annealing oven comprising a plurality of units,'each unit having an inner andan outer metallic wall spaced from each other, and edge portions forming a sealed vacuum chamber,' the opposite ends of said edge portions being mitered to cooperate with adjacent units in the forming of a rectangular oven chamber, and clamping means for holding-said units to each other.

T. An annealing oven comprising a plurality oi units cooperating to form an oven chamber, each unit having inner and outer Walls sealed to each other to form a vacuum chamber, and means-on each unitfor ex- 

